1. Field of the Invention
The present invention relates to the trigger mechanism for a firearm, and more particularly to a trigger mechanism that has a sear with a cam surface.
2. Related Art
There are a number of trigger mechanisms that have been used for firearms, including trigger mechanisms that are particularly designed for single-barrel pistols and multi-barrel pistols. In particular, there are double-action trigger mechanisms that have been designed for Derringer-type pistols. Additionally, there are existing trigger mechanisms which can maintain a constant pressure throughout a trigger pull and can allow for an adjustment of the pressure which is required for the trigger pull, i.e, the trigger pull weight. However, none of these known trigger mechanisms provide an operation that is as smooth and efficient as the trigger mechanism provided in the present invention. In particular, none of these known trigger mechanisms combine the mechanical advantage of a cam surface sear that works in combination with the trigger pull, linkage, hammer and hammer spring to control the trigger pull force as the hammer is forced to rotate from its striking position (i.e., seated position) to its rearward position (i.e., cocked position).
Small, light weight pistols, such as those made by Derringer, have been available for many years. While such pistols included double barrel pistols, they were not designed to provide a two shot capability (a so-called “double tap” shooting technique capability) without taking action other than by making successive trigger pulls. Thus, such pistols typically required some additional action by the shooter, such as the flipping of a lever, manually cocking the hammer, or the use of two triggers, in order to provide two shot capability. Even then, once the pistols of the prior art had been discharged they were not designed to be reloaded quickly, easily, or conveniently.
The prior art also included such single shot, small, light weight pistols as the “Liberator” which was quite inexpensive to manufacture and which included space within its butt where additional rounds of ammunition could be stored. Once again, however, the design of the Liberator pistol did not permit reloading to be quick, easy, or convenient. Further, the design of the Liberator pistol was such that it included numerous parts which were not “smoothly” integrated whereby that pistol could be quickly and reliably extricated from a pocket or other concealed location without a likelihood of some portion of the pistol (e.g., an external hammer) catching on the user's clothing, etc., which feature is especially important in a tactical situation.